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McALLEN — The U.S. and Mexico agreed to amend a 1944 water treaty, which might bring some relief to South Texas farmers struggling with scarce water.

The International Water and Boundary Commission, a federal agency that oversees international water treaties between the U.S. and Mexico, announced Saturday that the two countries had signed a highly-anticipated agreement that will give Mexico more options to meet its water deliveries to the U.S. Mexico still needs to give the U.S. more than a million acre-feet of water.

South Texas farmers and ranchers have been devastated lately by low rainfall and Mexico falling behind on its deliveries to the region.

Under the 1944 international treaty, Mexico must deliver 1,750,000 acre-feet of water to the U.S. from six tributaries every five years, or an average of 350,000 every year. But Mexico is at a high risk of not meeting that deadline. The country still has a balance of more than 1.3 million acre-feet of water it needs to deliver by October 2025.

The new amendment will allow Mexico to meet its delivery obligations by giving up water that was allotted to the country under the treaty. It also allows Mexico to transfer water it has stored at the Falcon and Amistad international reservoirs to the U.S.

Additionally, the agreement gives Mexico the option of delivering water it doesn’t need from the San Juan and Alamo rivers, which are not part of the six tributaries.

The amendment also addresses a current offer Mexico made to give the U.S. 120,000 acre-feet of water. South Texas farmers were wary of the offer because they worried that by accepting the water, the state would later force farmers to make up for it by giving up water they have been storing for next year.

But because the amendment allows Mexico to make use of water in its reservoirs to meet its treaty obligations, the farmers hope the country will transfer enough water for the next planting season to make up for any water they might have to give up.

"What's more important is we need water transferred at Amistad and Falcon," said Sonny Hinojosa, a water advocate for Hidalgo County Irrigation District No. 2, which distributes water to ranchers and farmers in the region. "If water gets transferred, they'll know they'll have a little bit of water for next year."

U.S. officials celebrated the signing of the amendment, which was initially meant to occur in December 2023. Mexican officials said they would not sign the agreement until after their presidential elections, which happened in June.

“The last thirty years of managing over-stretched water resources in the Rio Grande basin have produced broad agreement that the status quo was not acceptable,” IBWC commissioner Maria-Elena Giner said in a statement. “ With the signing of this [amendment], Mexico has tools for more regular water deliveries that can be applied right away.”

The amendment’s provisions that address current water delivery shortfalls expire in five years unless extended. The amendment also establishes longer-term measures such as an environmental working group to explore other sources of water. It also formalized the Lower Rio Grande Water Quality Initiative to address water quality concerns, including salinity.

Hinojosa said he’s concerned that by allowing Mexico to deliver water from the San Juan River, which is downstream from the reservoirs, the country won't feel as obligated to deliver water from the six tributaries managed by the treaty and still end up delivering less water to the Big Bend region. But he said he expects the agreement will bring some immediate relief.

“It’s going to get us some water, for now,” Hinojosa said. “Hopefully.”

Reporting in the Rio Grande Valley is supported in part by the Methodist Healthcare Ministries of South Texas, Inc.

This article originally appeared in The Texas Tribune at https://www.texastribune.org/2024/11/09/us-mexico-water-treaty-south-texas/.

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